Lord Falconer is expected to present yet another “assisted dying” Bill to Parliament this week. If it is anything like the draft Bill published last summer, it will not pass the public safety test. But let us reserve judgment on that until we have seen it.

There are, however, some fundamental issues here. To begin with, we need to be clear about what it is proposed to legalise.

The term “assisted dying” has no meaning in English law. It is a euphemism coined by campaigners. In plain language, what is being proposed is a law that would license doctors to supply lethal drugs to some terminally ill patients to help them commit suicide.

We have to ask ourselves: how could such a law be reconciled with public attitudes and government policies towards suicide? As a society, we go to considerable lengths to discourage and prevent suicide. We have “suicide watches” for individuals thought to be in danger of self-harm, and we have government-sponsored suicide-prevention programmes.

Yet now we are being told that there are some people (currently those who are terminally ill) whose suicide it is acceptable to assist.

Advocates of such a law tell us that they are not talking about suicide. They say that helping people who are terminally ill to end their lives is not assisting suicide because they are expected to die.

This is, of course, nonsense. In law, as in the English language, if you take your own life, whatever your state of health, that is suicide; and a doctor or anyone else who supplies you with the means to do so is assisting suicide. Sound law-making demands clarity. It cannot be based on euphemisms, verbal evasions or Orwellian spin.

The law that we have holds serious penalties in reserve to deter malicious assistance with suicide. But it also gives the Director of Public Prosecutions (DPP) discretion not to press charges where it is clear that such assistance has been given reluctantly, after genuine soul-searching and with compassionate motivation.

It is a law with a stern face but an understanding heart.

What is the result? Thanks to the deterrent effect of the law, assisting suicide is a rare offence in Britain today — about 20 cases a year cross the DPP’s desk. And, again thanks to the law’s deterrent effect, the handful of cases that do occur are generally those that do not call for prosecution. As the DPP himself told Lord Falconer’s self-styled “commission on assisted dying” 18 months ago, the law works well in practice.

What is now being proposed is something completely different. It is the creation of a licensing system for helping certain people (currently those who are terminally ill) to end their own lives.

Experience shows that enabling laws encourage the acts that they enable. Anyone inclined to doubt this should take a look at what is happening in Oregon, one of the handful of places around the world that have legalised assisted suicide and the model for those who want to see an “assisted dying” law here.

The number of legal assisted suicides annually in Oregon is nearly five times the level it was when the law was changed in 1998, and the numbers are rising.

Oregon’s current death rate from legal assisted suicide, if replicated in England and Wales, would produce more than 1,100 such deaths a year here.

We have to ask ourselves: are we prepared to accept this sort of death toll as a consequence of changing the law?

Three years ago, the Royal College of Physicians wrote to the DPP that a doctor’s duty of care for patients “does not include being in any way part of their suicide”.

It is a view with which the majority of doctors would concur, aware as they are of the vulnerabilities of terminally ill people.

“Assisted dying” is being commended to us on grounds of compassion. But compassion is common currency to both sides of this debate.

Compassion for an individual may prompt sympathy for a one-off act of assisted suicide, but compassion for all terminally ill people should make us wary of suggestions that we should license such acts by law.